Internal combustion engine control device

ABSTRACT

An internal combustion engine control device includes a partially-plugged filter capturing particulate matter in an exhaust gas from an internal combustion engine, having a plurality of cells, and having a structure in which some of the cells are closed on an inlet side and at least one of the other cells is opened on an outlet side or a structure in which some of the cells are closed on the outlet side and at least one of the other cells is opened on the inlet side, a PM sensor detecting an amount of PM in the exhaust gas which has passed through the partially-plugged filter, and an estimation portion estimating an amount of deposited PM of the partially-plugged filter according to an amount of PM detected by the PM sensor and a PM capturing rate of the partially-plugged filter.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2015-4188 filed on Jan. 13, 2015, the disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an internal combustion engine control device provided with a filter which captures particulate matter in an exhaust gas from an internal combustion engine.

BACKGROUND ART

A demand for an in-cylinder injection gasoline engine is expected to increase as fuel efficiency requirements are tightened for an internal combustion engine installed to a vehicle. However, an in-cylinder injection gasoline engine may possibly have a larger amount of PM (Particulate Matter) emission than an intake-port injection gasoline engine. In order to eliminate such a possibility, a filter capturing PM discharged from the engine is disposed in an exhaust passage of the engine.

In a system provided with such a PM capturing filter, it may become necessary to estimate an amount of deposited PM of the filter (an amount of PM deposited on the filter) when a filter recycle control (control to remove PM deposited on the filter by burning deposited PM), an abnormality diagnosis, and so on are performed.

A technique to estimate an amount of deposited PM of a PM capturing filter is disclosed in, for example, Patent Literature 1 (JP2007-262983A). According to the disclosed technique, an amount of deposited PM of the filter is calculated according to a front-back pressure difference of the filter, a flow rate of an exhaust gas, and an exhaust viscosity. An exhaust viscosity is corrected according to a flow rate of an exhaust gas at a same time.

A type of the PM capturing filter in the related art has a structure in which some of multiple cells provided to the filter are closed on an inlet side and the other cells (that is, inlet-opened cells) are closed on an outlet side.

PRIOR ART LITERATURES Patent Literature

Patent Literature 1: JP2007-262983A

SUMMARY OF INVENTION

The filter in the related art is configured in such a manner that once an exhaust gas flows into the inlet-opened cells, substantially the entire exhaust gas flows out from the outlet-opened cells by passing across dividing walls (partition walls) having a porous structure and defining the cells and PM in the exhaust gas is captured while the exhaust gas passes across the dividing walls. The filter in the related art, however, has a deficit that a pressure loss of exhaust increases.

In order to reduce a pressure loss of exhaust caused by the filter, the inventor has been studying a system provided with a partially-plugged filter having a structure in which some of multiple cells are closed on the inlet side and at least one of the other cells is opened on the outlet side (or a structure in which some cells are closed on the outlet side and at least one of the other cells is opened on the inlet side).

When the system provided with a partially-plugged filter is employed, a pressure loss of exhaust caused by the filter can be reduced. However, when a pressure loss is reduced, a front-back pressure difference of the filter caused by deposited PM becomes small. It is therefore difficult to estimate an amount of deposited PM of the filter at high accuracy by estimating an amount of deposited PM of the filter using a front-back pressure difference of the filter as the technique disclosed in Patent Literature 1. In addition, the technique disclosed in Patent Literature 1 requires a pressure difference sensor to detect a front-back pressure difference of the filter. Hence, the inventor discovered a problem that costs and complexity of the system are increased.

An object of the present disclosure is to provide an internal combustion engine control device capable of estimating an amount of deposited PM of a PM capturing filter at high accuracy without increasing costs and complexity of a system.

According to an aspect of the present disclosure, the internal combustion engine control device includes a partially-plugged filter capturing particulate matter in an exhaust gas from an internal combustion engine, having a plurality of cells, and having a structure in which some of the cells are closed on an inlet side and at least one of the other cells is opened on an outlet side or a structure in which some of the cells are closed on the outlet side and at least one of the other cells is opened on the inlet side, a PM sensor detecting an amount of PM in the exhaust gas which has passed through the partially-plugged filter, and an estimation portion estimating an amount of deposited PM of the partially-plugged filter according to an amount of PM detected by the PM sensor and a PM capturing rate of the partially-plugged filter.

A predetermined correlation is established among an amount of deposited PM of the partially-plugged filter, an amount of PM detected by the PM sensor (an amount of PM which has passed through the partially-plugged filter), and a PM capturing rate of the partially-plugged filter. Hence, an amount of deposited PM can be estimated (calculated) by using an amount of PM detected by the PM sensor and a PM capturing rate. In this case, because an amount of deposited PM can be estimated without using a front-back pressure difference of the partially-plugged filter 31, an amount of deposited PM can be estimated at high accuracy even when an amount of deposited PM is small and hence a front-back pressure difference of the partially-plugged filter 31 is small. In addition, it is not necessary to provide a pressure difference sensor to detect a front-back pressure difference of the partially-plugged filter 31. Hence, an increase in costs and complexity of the system can be avoided.

BRIEF DESCRIPTION OF DRAWINGS

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

FIG. 1 is a view showing a schematic configuration of an engine control system according to one embodiment of the present disclosure;

FIG. 2 is a sectional view of a partially-plugged filter taken along a flow direction of an exhaust gas;

FIG. 3 is a sectional view of the partially-plugged filter on an inlet side taken along a direction orthogonal to the flow direction of an exhaust gas;

FIG. 4 is a sectional view of the partially-plugged filter on an outlet side taken along a direction orthogonal to the flow direction of an exhaust gas;

FIG. 5 is an output characteristic view of a linear PM sensor;

FIG. 6 is an output characteristic view of an integration PM sensor;

FIG. 7 is a time chart used to describe a recycle control;

FIG. 8 is a view showing a relation of an amount of deposited PM and a PM capturing rate;

FIG. 9 is a view showing a relation of a flow rate of an exhaust gas and a PM capturing rate;

FIG. 10 is a view showing a relation of an exhaust pressure and a PM capturing rate;

FIG. 11 is a view showing a relation of a temperature of an exhaust gas and a PM capturing rate;

FIG. 12 is a view showing a relation of an amount of deposited ash and a PM capturing rate; and

FIG. 13 is a flow chart depicting a flow of processes in a PM deposition amount estimation routine.

DESCRIPTION OF EMBODIMENT

Hereinafter, one concrete embodiment to carry out present disclosure will be described.

A schematic configuration of an engine control system will be described according to FIG. 1.

An engine 11 is an in-cylinder injection internal combustion engine, and more specifically, an in-cylinder injection gasoline engine configured to directly inject gasoline as fuel into cylinders. An air cleaner 13 is provided to an uppermost stream portion of an intake pipe 12 of the engine 11. An airflow meter 14 detecting an amount of intake air is provided downstream of the air cleaner 13. A throttle valve 16 driven by a motor 15 to open at a regulated opening degree and a throttle opening degree sensor 17 detecting an opening degree of the throttle valve 16 (degree of throttle opening) are provided downstream of the airflow meter 14.

A surge tank 18 is provided downstream of the throttle valve 16 and the surge tank 18 is provided with an intake pipe pressure sensor 19 detecting an intake pipe pressure. The surge tank 18 is also provided with an intake manifold 20 introducing air into respective cylinders of the engine 11. A fuel injection valve 21 is attached to each cylinder of the engine 11 and directly injects fuel (gasoline) into the cylinder. A sparking plug 22 is attached to a cylinder head of the engine 11 for each cylinder. An air-fuel mixture in each cylinder is ignited by a spark discharge of the sparking plug 22 attached to the cylinder.

Meanwhile, an exhaust gas sensor 24 (an air-fuel ratio sensor, an oxygen sensor, or the like) detecting an air-fuel ratio of an exhaust gas or whether an air-fuel ratio is lean or rich is provided to an exhaust pipe 23 of the engine 11. A catalyst 25, such as a three-way catalyst, cleaning CO, HC, NOR, and so on in an exhaust gas is provided downstream of the exhaust gas sensor 24.

A partially-plugged filter 31 capturing PM (Particulate Matter) in an exhaust gas from the engine 11 is provided downstream of the catalyst 25 in the exhaust pipe 23 of the engine 11. The catalyst 25 and the partially-plugged filter 31 may be stored in a single case or stored in separate cases. Further, a PM sensor 32 detecting an amount of PM in an exhaust gas which has passed through the partially-plugged filter 31 is provided downstream of the partially-plugged filter 31.

A coolant temperature sensor 26 detecting a coolant temperature and a knocking sensor 27 detecting knocking are attached to a cylinder block of the engine 11. A crank angle sensor 29 outputting a pulse signal each time a crank shaft 28 rotates by a predetermined crank angle is attached to an outer periphery side of the crank shaft 28. A crank angle and an engine speed are detected according to an output signal of the crank angle sensor 29.

Outputs of the various sensors are inputted into an electronic control unit (ECU) 30. The ECU 30 is chiefly formed of a micro-computer and controls an injection amount of fuel, ignition timing, a degree of throttle opening (an amount of intake air), and so on according to an engine running condition by executing various engine control programs preliminarily stored in an internal ROM (memory medium). In the present embodiment, the internal combustion engine control device has the partially-plugged filter 31, the PM sensor 32, and the ECU 30.

As are shown in FIG. 2 through FIG. 4, the partially-plugged filter 31 includes multiple cells 33 extending in a flow direction of an exhaust gas (a direction heading from an inlet side to an outlet side) and defined by dividing walls (partition walls) 34 having a porous structure. Some of the cells 33 are closed by a sealing member 35 at ends on an inlet side and all of the cells 33 are opened on an outlet side. In the present embodiment, let a cell closed on the inlet side and opened on the outlet side be an inlet-closed cell 33A and a cell opened on both of the inlet side and the outlet side be a double-side open cell 33B, then the cells 33A and 33B are situated next to each other alternately.

In the partially-plugged filter 31, when an exhaust gas flows into the double-side open cells 33B from the inlet side of the double-side open cells 33B, an internal pressure of the double-side open cells 33B rises. Accordingly, an internal pressure of the inlet-closed cells 33A becomes low relative to an internal pressure of the double-side open cells 33B. Hence, a part of the exhaust gas in the double-side open cells 33B flows into the inlet-closed cells 33A by passing across the dividing walls 34 having a porous structure and flows outside of the inlet-closed cells 33A from the outlet side of the inlet-closed cells 33A. While the exhaust gas flows in and out in the manner as above, PM (for example, soot particles having a particle size of 20 to 100 nm) in the exhaust gas adheres to pore inner portions (inner wall surfaces of pores) and outer layers of wall surfaces of the dividing walls 34 and is thus captured. Ash, which is a non-combustible substance (for example, ash content generated from oil in the engine 11) in the exhaust gas, adheres to the pore inner portions and the outer layers of the wall surfaces of the dividing walls 34 and is thus also captured.

It is preferable to use a linear PM sensor having a linear output characteristic as the PM sensor 32. However, an integration PM sensor having an integration output characteristic may be used as well. As is shown in FIG. 5, a sensor output of the linear PM sensor varies linearly in response to an amount of PM in an exhaust gas. On the other hand, as is shown in FIG. 6, a sensor output of the integration PM sensor varies in response to an integration value of an amount of PM after an integration value of an amount of PM adhered to the PM sensor reaches or exceeds a constant value.

In the system provided with the partially-plugged filter 31 that captures the PM, a pressure loss of exhaust increases when an amount of deposited PM of the partially-plugged filter 31 (an amount of PM deposited on the partially-plugged filter 31) becomes too large. In order to eliminate such an inconvenience, as is shown in FIG. 7, the ECU 30 recycles the partially-plugged filter 31 by performing a recycle control by which PM captured in the partially-plugged filter 31 is removed by burning the captured PM (that is, reduce an amount of deposited PM of the partially-plugged filter 31). The recycle control includes, for example, a fuel cut control performed when a predetermined fuel cut execution condition is satisfied (for example, during deceleration). When an amount of deposited PM of the partially-plugged filter 31 exceeds a predetermined upper-limit value (see FIG. 7), the ECU 30 performs a control to make an air-fuel ratio lean or a control to raise an exhaust temperature as the recycle control.

During the recycle control, the ECU 30 performs a PM deposition amount estimation routine of FIG. 13 in the present embodiment to estimate an amount of deposited PM of the partially-plugged filter 31 according to an amount of sensor-detected PM, which is an amount of PM detected by the PM sensor 32, and a PM capturing rate of the partially-plugged filter 31.

A predetermined correlation (a relation expressed by Equation (1) below) is established among an amount of deposited PM (for example, an amount of deposited PM per predetermined time), an amount of sensor-detected PM (for example, an amount of PM which has passed through the partially-plugged filter 31 per predetermined time), and a PM capturing rate.

An amount of deposited PM=An amount of sensor-detected PM×PM capturing rate/(1−PM capturing rate)  (1)

Hence, an amount of deposited PM can be estimated (calculated) in accordance with Equation (1) above by using an amount of sensor-detected PM and a PM capturing rate.

The partially-plugged filter 31 has a characteristic that a PM capturing rate varies with an amount of deposited PM. More specifically, as is shown in FIG. 8, after PM is removed from the partially-plugged filter 31 (an amount of deposited PM is reduced to substantially 0) by the recycle control or the like, PM deposits in the pores of the dividing walls 34 and then PM deposits on the outer layers of the wall surfaces of the divining walls 34. In an in-pore depositing region in which PM deposits in the pores of the dividing walls 34 (a region in which an amount of deposited PM is relatively small), a PM capturing rate rises once with an increase in an amount of deposited PM and decreases later. Afterwards, a PM capturing rate remains substantially constant in an outer-layer depositing region in which PM deposits on the outer layers of the wall surfaces of the dividing walls 34. By taking the characteristic as above into consideration, in the present embodiment, a PM capturing rate used in an estimation of an amount of deposited PM is changed in response to a last value (an integration value up to a last time) of the amount of deposited PM.

The partially-plugged filter 31 has another characteristic that a PM capturing rate varies with a flow rate of an exhaust gas passing through the partially-plugged filter 31. More specifically, as is shown in FIG. 9, a PM capturing rate of the partially-plugged filter 31 becomes substantially constant in a region in which a flow rate of an exhaust gas is relatively low whereas a PM capturing rate decreases in a region in which a flow rate of an exhaust gas is relatively high because a flow rate of an exhaust gas which flows past the partially-plugged filter 31 without passing across the dividing walls 34 rises (that is, a flow rate of an exhaust gas passing across the dividing walls 34 falls) as a flow rate of an exhaust gas rises. By taking the characteristic as above into consideration, in the present embodiment, a PM capturing rate used in the estimation of the amount of deposited PM is changed in response to a flow rate of an exhaust gas passing through the partially-plugged filter 31.

The partially-plugged filter 31 has still another characteristic that a PM capturing rate varies with an exhaust pressure on an upstream side of the partially-plugged filter 31. More specifically, as is shown in FIG. 10, a PM capturing rate of the partially-plugged filter 31 rises as an exhaust pressure becomes higher because a flow rate of an exhaust gas passing across the dividing walls 34 rises. By taking the characteristic as above into consideration, in the present embodiment, a PM capturing rate used in the estimation of the amount of deposited PM is changed in response to an exhaust pressure on the upstream side of the partially-plugged filter 31.

The partially-plugged filter 31 has still another characteristic that a PM capturing rate varies with a temperature of an exhaust gas flowing into the partially-plugged filter 31. More specifically, as is shown in FIG. 11, a PM capturing rate of the partially-plugged filter 31 rises as a temperature of an exhaust gas rises because Brownian motion of PM becomes more active. By taking the characteristic as above into consideration, in the present embodiment, a PM capturing rate used in the estimation of the amount of deposited PM is changed in response to a temperature of an exhaust gas flowing into the partially-plugged filter 31. Alternatively, a PM capturing rate used in the estimation of the amount of deposited PM may be changed in response to a temperature of an exhaust gas flowing out from the partially-plugged filter 31 or a temperature of the partially-plugged filter 31.

The partially-plugged filter 31 has still another characteristic that a PM capturing rate varies with an amount of deposited ash of the partially-plugged filter 31. More specifically, as is shown in FIG. 12, a PM capturing rate of the partially-plugged filter 31 decreases as an amount of deposited ash increases because a flow rate of an exhaust gas passing across the dividing walls 34 and a flow rate of an exhaust gas coming into contact with the dividing walls 34 fall. By taking the characteristic as above into consideration, in the present embodiment, a PM capturing rate used in the estimation of the amount of deposited PM is changed in response to an amount of deposited ash of the partially-plugged filter 31.

In short, in the present embodiment, a PM capturing rate used in the estimation of the amount of deposited PM is changed in response to parameters, such as an amount of deposited PM, a flow rate of an exhaust gas, an exhaust pressure, a temperature of an exhaust gas, and an amount of deposited ash in consideration of the characteristics that a PM capturing rate varies with the parameters specified above.

The following will describe a content of processes in the PM deposition amount estimation routine of FIG. 13 performed by the ECU 30 in the present embodiment.

The PM deposition amount estimation routine shown in FIG. 13 is performed repetitively in predetermined cycles while a power supply of the ECU 30 is turned on and functions as an estimation portion. When the routine is started, whether the recycle control is being performed is determined in 101. When it is determined that the recycle control is being performed, the routine is ended without performing processes in and after 102.

Meanwhile, when it is determined in 101 that the recycle control is not being performed, advancement is made to 102, in which an amount of deposited PM at an end of the recycle control is calculated as an initial value of an amount of deposited PM. In a case where a performance time of the recycle control is as long as or longer than a predetermined time (time necessary to remove PM deposited on the partially-plugged filter 31), an initial value of an amount of deposited PM is set to “0”. On the other hand, in a case where a performance time of the recycle control is shorter than the predetermined time, an initial value of an amount of deposited PM (an amount of deposited PM at an end of the recycle control) is calculated according to an amount of deposited PM at a beginning of the recycle control, a performance time of the recycle control, a temperature of the partially-plugged filter 31, and so on with reference to a map or in accordance with a mathematical formula.

Subsequently, advancement is made to 103, in which an amount of PM detected by the PM sensor 32 (for example, an amount of PM which has passed through the partially-plugged filter 31 per predetermined time) is loaded as an amount of sensor-detected PM.

Subsequently, advancement is made to 104, in which a base PM capturing rate is calculated according to the initial value or the last value of an amount of deposited PM with reference to a map or in accordance with a mathematical formula. A base PM capturing rate immediately after an end of the recycle control (first time after an end of the recycle control) is calculated according to the initial value of an amount of deposited PM with reference to a map or the like. Afterwards, the base PM capturing rate is calculated according to the last value of an amount of deposited PM (an integration value up to a last time) with reference to a map or the like. A map or a mathematical formula of the base PM capturing rate is prepared in advance according to test data, design data, and so on in consideration of a relation of an amount of deposited PM and a PM capturing rate (see FIG. 8) and preliminarily stored in the ROM of the ECU 30.

Subsequently, advancement is made to 105, in which a first correction coefficient of a PM capturing rate is calculated according to a flow rate of an exhaust gas passing through the partially-plugged filter 31 with reference to a map or in accordance with a mathematical formula. Herein, for example, a flow rate of intake air is used as information alternative to a flow rate of an exhaust gas. Alternatively, a flow rate of an exhaust gas may be calculated according to an engine running condition (for example, an engine speed or an engine load). A map or a mathematical formula of the first correction coefficient is prepared in advance according to test data, design data, and so on in consideration of a relation of a flow rate of an exhaust gas and a PM capturing rate (see FIG. 9) and preliminarily stored in the ROM of the ECU 30.

Subsequently, advancement is made to 106, in which a second correction coefficient of a PM capturing rate is calculated according to an exhaust pressure on the upstream side of the partially-plugged filter 31 with reference to a map or in accordance with a mathematical formula. Herein, an exhaust pressure is calculated according to an engine running condition (for example, an engine speed and an engine load). Alternatively, in a case where the system includes a pressure sensor detecting an exhaust pressure on the upstream side of the partially-plugged filter 31, an exhaust pressure detected by the pressure sensor is used. A map or a mathematical formula of the second correction coefficient is prepared in advance according to test data, design data, and so on in consideration of a relation of an exhaust pressure and a PM capturing rate (see FIG. 10) and preliminarily stored in the ROM of the ECU 30.

Subsequently, advancement is made to 107, in which a third correction coefficient of a PM capturing rate is calculated according to a temperature of an exhaust gas flowing into the partially-plugged filter 31 with reference to a map or in accordance with a mathematical formula. Herein, a temperature of an exhaust gas is calculated according to an engine running condition (for example, an engine speed and an engine load). Alternatively, in a case where the system includes a temperature sensor detecting a temperature of an exhaust gas flowing into the partially-plugged filter 31, a temperature of an exhaust gas detected by the temperature sensor is used. A map or a mathematical formula of the third correction coefficient is prepared in advance according to test data, design data, and so on in consideration of a relation of a temperature of an exhaust gas and a PM capturing rate (see FIG. 11) and preliminarily stored in the ROM of the ECU 30. Alternatively, the third correction coefficient of a PM capturing rate may be calculated according to a temperature of an exhaust gas flowing out from the partially-plugged filter 31 or a temperature of the partially-plugged filter 31 with reference to the map or in accordance with the mathematical formula.

Subsequently, advancement is made to 108, in which a fourth correction coefficient of a PM capturing rate is calculated according to an amount of deposited ash of the partially-plugged filter 31 with reference to a map or in accordance with a mathematical formula. Herein, an amount of deposited ash is calculated according to an engine running condition (for example, an engine speed and an engine load). A map or a mathematical formula of the fourth correction coefficient is prepared in advance according to test data, design data, and so on in consideration of a relation of an amount of deposited ash and a PM capturing rate (see FIG. 12) and preliminarily stored in the ROM of the ECU 30.

Subsequently, advancement is made to 109, in which a final PM capturing rate is found by correcting the base PM capturing rate using the first to fourth correction coefficients. By the processes in 104 to 109 as above, a PM capturing rate used in the estimation of the amount of deposited PM is changed in response to parameters, such as an amount of deposited PM, a flow rate of an exhaust gas, an exhaust pressure, a temperature of an exhaust gas, and an amount of deposited ash in consideration of the characteristics that a PM capturing rate varies with the parameters specified above.

Subsequently, advancement is made to 110, in which a present amount of deposited PM (for example, an amount of deposited PM per predetermined time) is estimated (calculated) in accordance with Equation (1) above by using an amount of sensor-detected PM and a PM capturing rate. Subsequently, advancement is made to 111, in which an integration value of an amount of deposited PM up to a present time is found by adding the present amount of deposited PM to an integration value of an amount of deposited PM up to the last time.

In the present embedment described above, an amount of deposited PM of the partially-plugged filter 31 is estimated according to an amount of PM detected by the PM sensor 32 (an amount of sensor-detected PM) and a PM capturing rate of the partially-plugged filter 31. A predetermined correlation is established among an amount of deposited PM, an amount of sensor-detected PM, and a PM capturing rate. Hence, an amount of deposited PM can be estimated (calculated) by using an amount of sensor-detected PM and a PM capturing rate. In this case, because an amount of deposited PM can be estimated without using a front-back pressure difference of the partially-plugged filter 31, an amount of deposited PM can be estimated at high accuracy even when an amount of deposited PM is small and hence a front-back pressure difference of the partially-plugged filter 31 is small. In addition, it is not necessary to provide a pressure difference sensor to detect a front-back pressure difference of the partially-plugged filter 31. Hence, an increase in costs and complexity of the system can be avoided.

In the present embodiment, a PM capturing rate used in the estimation of the amount of deposited PM is changed in response to parameters, such as an amount of deposited PM, a flow rate of an exhaust gas, an exhaust pressure, a temperature of an exhaust gas, and an amount of deposited ash in consideration of the characteristics that a PM capturing rate varies with the parameters specified above. Accordingly, a PM capturing rate used in the estimation of the amount of deposited PM can be set to a suitable value by changing the PM capturing rate to suit a variance in PM capturing rate in response to an amount of deposited PM, a flow rate of an exhaust gas, an exhaust pressure, a temperature of an exhaust gas, an amount of deposited ash, and so on. Consequently, estimate accuracy of an amount of deposited PM can be increased.

The embodiment above is configured in such a manner that a PM capturing rate used in the estimation of the amount of deposited PM is changed in response to all of an amount of deposited PM, a flow rate of an exhaust gas, an exhaust pressure, a temperature of an exhaust gas, and an amount of deposited ash. However, the present disclosure is not limited to the configuration as above. A PM capturing rate used in the estimation of the amount of deposited PM may be changed in response to one or two or more of an amount of deposited PM, a flow rate of an exhaust gas, an exhaust pressure, a temperature of an exhaust gas, and an amount of deposited ash.

In the embodiment above, the present disclosure is applied to a system provided with a partially-plugged filter having a structure in which some cells are closed on an inlet side and all cells are opened on an outlet side. However, an application of the present disclosure is not limited to the system as above. The present disclosure may be applied to a system provided with a partially-closed filter having a structure in which some cells are closed on an inlet side and some of the other cells (inlet-opened cells) are closed on an outlet side. Alternatively, the present disclosure may be applied to a system provided with a partially-plugged filter having a structure in which some cells are closed on an outlet side and all cells are opened on an inlet side, or a partially-plugged filter having a structure in which some cells are closed on an outlet side and some of the other cells (outlet-opened cells) are closed on an inlet side. In short, the present disclosure can be applied to any system provided with a partially-plugged filter having a structure in which some cells are opened on both of an inlet side and an outlet side.

In the embodiment above, the present disclosure is applied to a system equipped with an in-cylinder injection gasoline engine. However, an application of the present disclosure is not limited to the system as above. The present disclosure can be applied to any system provided with a partially-plugged filter even when the system is equipped with a diesel engine or an intake-port injection gasoline engine.

While the present disclosure has been described with reference to embodiments thereof, it is to be understood that the disclosure is not limited to the embodiments and constructions. The present disclosure is intended to cover various modification and equivalent arrangements. In addition, while the various combinations and configurations, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the present disclosure. 

1. An internal combustion engine control device, comprising: a partially-plugged filter capturing particulate matter in an exhaust gas from an internal combustion engine, the partially-plugged filter having a plurality of cells, and the partially-plugged filter having a structure in which some of the cells are closed on an inlet side and at least one of the other cells is opened on an outlet side or a structure in which some of the cells are closed on the outlet side and at least one of the other cells is opened on the inlet side; a PM sensor detecting an amount of PM in the exhaust gas which has passed through the partially-plugged filter; and an estimation portion estimating an amount of deposited PM of the partially-plugged filter according to an amount of PM detected by the PM sensor and a PM capturing rate of the partially-plugged filter.
 2. The internal combustion engine control device according to claim 1, wherein the estimation portion changes the PM capturing rate used in an estimation of the amount of deposited PM, in response to the amount of deposited PM.
 3. The internal combustion engine control device according to claim 1, wherein the estimation portion changes the PM capturing rate used in an estimation of the amount of deposited PM, in response to a flow rate of an exhaust gas passing through the partially-plugged filter.
 4. The internal combustion engine control device according to claim 1, wherein the estimation portion changes the PM capturing rate used in an estimation of the amount of deposited PM, in response to an exhaust pressure on an upstream side of the partially-plugged filter.
 5. The internal combustion engine control device according to claim 1, wherein the estimation portion changes the PM capturing rate used in an estimation of the amount of deposited PM, in response to at least one of a temperature of an exhaust gas flowing into the partially-plugged filter, a temperature of an exhaust gas flowing out from the partially-plugged filter, or a temperature of the partially-plugged filter.
 6. The internal combustion engine control device according to claim 1, wherein the estimation portion changes the PM capturing rate used in an estimation of the amount of deposited PM, in response to an amount of deposited ash of the partially-plugged filter. 